Unleaded. 10 years on.

[warren t claim]

What's the Autoshite opinion on lead replacement additives?

 

Does anyone here run a car with non hardened valve seats using Tetraboost or similar?

 

Is it reasonable to expect a car that was designed to run on 4* to be happy with additives in the fuel?

[Minimad5]

My fiesta runs on fuel supplements and seems to be okay

I have used quarter of a tank without this supplement business and it went a tadge smokey, but seems okay now.

(If it smokes again and runs likes sh*t, then valves shall be inspected) .... BUT it seems okay.

[wuvvum]

I use Redex in the Volvo and the R6. The Renault is fine with unleaded + Redex, but the Volvo pinks like a bastard on 95 octane, and doesn't really like 97 octane that much, so if I'm going to be doing a long run or driving it hard I add a dash of octane booster as well.

[Pete-M]

I've never used any octane boosting stuff in anything, or had any problems either. 10.5:1 CR Rover P6s do need the ignition timing knocking back a tiny bit if run exclusively on standard unleaded and thrashed regularly, but I've always found that if I put some super unleaded in every now and then there's no issue at all with pinking if it the car is running right.. This has worked on everything I've owned that is meant to be run on 4 or 5 star leaded fuel.

 

Everything that ran on 2 or three star seems happy with boggo supermarket unleaded.

 

205 GTis can suffer from valve seat recession, but I suspect that has more to do with regular trips to the redline than no lead in the fuel. If anyone has one that has done 40k without needing the valve clearances adjusting I'll be surprised...

 

I don't doubt that octane boosters can make a difference, but I've never owned the same car for more than 40k miles and I've run quite a few 'leaded only' cars for 20-25k with zero signs of any problems, so I don't think there's a big risk of any damage on lots of cars.

 

The older stuff I've owned tends to have had engines designed in the 50's, and that stuff will run on almost anything remotely flammable anyway.

 

The Jag is happy on cheap unleaded, and it uses enough fuel to mean putting super in wouldn't take long to make a difference if there was one to be had, but Jag recommend running the thing on the cheap stuff so that's good enough for me.

[Richard]

The Peugeot 505 engine was supposed to be leaded only but we used to do 200k in them on unleaded, on top of the 100k they usually had when we got them.

[ashmicro]

A mate uses the Lead Replacement stuff in regular unleaded on his 'Scrote. 1987 1.3 OHV Valencia with distributor. No issues, although this may not be a good example, as those engines are pretty much unkillable.

[Rusty Pelican]

Never bothered with the stuff , the cost I figured is greater than changing valves every 5 years or so , although ive not had to do that yet either

[theorganist]

I run the 14 on unleaded without any problems. I put some additive (Redex) in when I am going on a longer run.

 

I used unleaded in the Maxi and 1100 with additive also, with no problems.

[Mr Lobster]

R4 only gets Redex if I'm going on a long motorway speed run. Otherwise seems ok on normal unleaded.

[Guest]

The Amazon's engine has enough issues without worrying about valve seat recession. I've run it on 95 unleaded since I've owned it and the previous owner did the same. I suspect you could run that engine on piss if it had combustible properties, it doesn't seem to care. When the B20 (well, technically B22) eventually goes in I'll lob some hardened valve seats at it because I'll be in more of a position to do so.

 

Piazza was always run on unleaded - it was designed to run on it, as was the 480. Incidentally, that has a window sticker saying it can run on 4 star or unleaded.

[Conrad D. Conelrad]

The Herald has been running on unleaded with a squirt of Valvemaster for the last decade, and when I overhauled the head the valves and seats were in excellent condition.

[Anglevan]

My mate ran a 1964 Ford Anglia for at least 40,000 was fine until the last 5000 or so when the car got very tappety. Still ran ok'ish and we never did take the head off but it clearly suffered from some valve seat recession. (we did adjust em up but kept getting noisy again, car was sold before investigating any further)

I'll only run my Capri with addative however saying that I have managed to obtain some very late 2.8 heads which are unleaded from factory but i cant see me fitting em unless something major happens.

The Lancer / Fiesta / Talbot camper all run happily on unleaded with no issues

[Richard]

Valve seat recession doesn't make the engine tappety, it closes the valve clearances.