Hello! I have done a lot of research in the past and always came across one fact in the USA. That car manufacturers always recommended 10w30 instead of 5w30 for high horsepower engines! For example:
1. Jeep recommended in owners manual for 4,7l V8 5w30 and for the 4,7l V8 High Output which had about 30 hp more they recommended 10w30
2. Tuning magazine recommended owner of Dodge Neon SRT Mobil 1 5w30 if driven normal and Mobil 10w30 when driven hard!
3. Genuine Mopar oil in the 90s was 10w40 Sj rated, 10w30 Turbo approved for high performance engines and 5w30 All Season fuel efficient
4. Gm recmmended for Trans Am Turbo at the beginning of the 80s SF rated 10w30 and 5w30 for low temperatures
My question is if anybody knows why manufacturers wanted in their High performnce engines an oil which didn´t flow as fast as 5w30 would and why the didn´t recommend 10w40 which would be more thick than 10w30 in high temperatures which occur in high performnce engines! I´m talkiing bout times when synthetics weren´t that common in the USA!
HEre in austria we had at the beginning of the 90s the synthetic oil wave, when every oil manufacturer began to offer full synthetics in 5w40 and 5w50 and castrol even offered a 10w60 which were used in in multivalve and turbo engines!
Does anybody have an answer, would be very interested!
1. Jeep recommended in owners manual for 4,7l V8 5w30 and for the 4,7l V8 High Output which had about 30 hp more they recommended 10w30
2. Tuning magazine recommended owner of Dodge Neon SRT Mobil 1 5w30 if driven normal and Mobil 10w30 when driven hard!
3. Genuine Mopar oil in the 90s was 10w40 Sj rated, 10w30 Turbo approved for high performance engines and 5w30 All Season fuel efficient
4. Gm recmmended for Trans Am Turbo at the beginning of the 80s SF rated 10w30 and 5w30 for low temperatures
My question is if anybody knows why manufacturers wanted in their High performnce engines an oil which didn´t flow as fast as 5w30 would and why the didn´t recommend 10w40 which would be more thick than 10w30 in high temperatures which occur in high performnce engines! I´m talkiing bout times when synthetics weren´t that common in the USA!
HEre in austria we had at the beginning of the 90s the synthetic oil wave, when every oil manufacturer began to offer full synthetics in 5w40 and 5w50 and castrol even offered a 10w60 which were used in in multivalve and turbo engines!
Does anybody have an answer, would be very interested!